Planishing device and method

ABSTRACT

A planishing device ( 10 ) with a pulling element ( 11 ) and lever arms (151.1, 151.2) connected in an articulated manner, with bearing elements ( 12.1, 12.2 ) for bearing on a material layer (WS), characterised in that the lever arms ( 151.1, 151.2 ) in the region of the end ( 158.1, 158.2 ) lying opposite their grip are connected in an articulated manner to a joint member ( 157 ) connecting the lever arms ( 151.1, 151.2 ) at a location ( 161 ) distanced from these ends ( 158.1, 158.2 ), are supported in an articulated and movable manner via supports ( 162.1, 162.2 ) on a supporting element ( 16 ) that is interactively connected to the bearing elements ( 12.1, 12.2 ). Pulling element ( 11 ) is connected to joint member ( 157 ) via a rod ( 154 ).

The invention relates to a planishing device and to a planishing methodaccording to the patent claims 1 and 11.

There are known various devices for repairing dent-like or orindentation-like deformations on vehicles. From EP 681 876 there isknown a lever device which by way of one or more levers supported at onepoint permits the planishing from the inner side of a deformed car bodysheet. This device has the disadvantage that the inner side to betreated as a rule does not lay bare and that a precise handling is madedifficult on account of the lever which is supported only at one point.Basically single lever devices also have the additional disadvantagethat forces are transmitted onto the location to be treated or thesupport location in an oblique manner.

U.S. Pat. No. 4,026,139 shows a lever device with a lever pair which ismounted in the middle region in an articulated manner. A suction cap ineach case is fastened at the end of each of the levers via a linkage. AU-shaped pulling element is pivotally linked in the linkage point of thelever pair and at the free end likewise comprises a suction cap which isto be placed at the location of the dent. Although this design has anadjustment possibility on account of additional bores on the two levers,it is however not suitable for the regularly required adjustments sincethe respective adjustment on the one hand is complicated and on theother hand on handling, it effects unequal lever lengths and leverforces as well as undesirable movement paths. This design may not beapplied with a sufficient flexibility to more complex workpieces. Inaddition, above all with larger dents the distance of the two supportlocations compellingly changes during the planishing procedure, whichresults in the danger of scratches or in a handling which is difficultto control.

Various conventional planishing devices, thus for example U.S. Pat. No.4,089,201, and U.S. Pat. No. 3,635,072 show designs with pullingelements which are adjustable with threaded rods and which may beadjusted by way of rotating wing nuts and likewise. These solutions arevery bad to operate, above all when their actuation is to be carried outby a single operating person. Furthermore undesirable operating forcesare required so that as a rule a hand operation is not possible as withU.S. Pat. No. 3,635,072.

The above described devices also have the common disadvantage that thedevices are difficult to apply on the material to be planished, sincethe support parts as well as the pulling part of the devices must beapplied essentially simultaneously. Although a later adjustment ispossible with the mentioned lever design according to EP 681876, thishowever has the disadvantage that the support location for its part isloaded too greatly when it directly engages the material.

There are known further devices such as e.g. U.S. Pat. No. 4,089,201which must penetrate the dent location in order to permit itsplanishing. It may however be easily deduced that this creates a later,additional repair effort which is to be avoided if possible. Belongingto the state of the art is also a single lever design with which thesheet to be planished is not pressed from the inside but is pulled fromthe outside, wherein its pulling element is adhesed in the dent regionby way of adhesive. This solution too does not ensure any controlledforce effect or a sufficiently fine and exact control of the pullingforce which is exerted with this, and leads to an excess loading of thebearing location.

It is the object of the invention to provide a planishing device and aplanishing method which may be easily operated with low actuationforces, permits a secure and simple support on the workpiece to betreated, is flexibly adjustable, if desired with an adjustability alsoduring use, and leads to low counterforces on the bearing location.

This object is achieved by the invention defined in the patent claims.

The invention for the first time provides a device and a method forrepairing dented or indented material layers, in particular car bodiesof metal sheet or plastic which with low operating forces permit ametered force effect on the dent location to be re-shaped and onapplication as well as optionally when required, have an simple andflexible adjustability of the device.

The concept of the invention is based on the fact that the counterforceswhich counteract the necessary planishing force are distributed on atleast two feet of bearing elements, wherein the force effect isintroduced onto the pulling element essentially uniformly at all timesvia at least two adjustable levers acting on the pulling element.

For this purpose the planishing device contains two or more lever armswhich in the region of their end lying opposite the grip are connectedin an articulated manner to a joint member connecting the lever arms.The lever arms at a location distanced from these ends are supported ona supporting element in an articulated and movable manner via supportmeans. The pulling element for its part is connected to the jointmember. The supporting element is interactively connected to at leasttwo bearing elements which for their part support the planishing devicewith respect to the workpiece to be treated.

The lever device of a planishing device according to the inventionpreferably has two lever arms with a transmission ratio of at leastabout 3:1.

Preferably at the same time the operating end of the pulling element isreleasably connected to a connection element which has an end surfacefor connection to the material layer to be treated. This connection ofthe end surface to the material layer in a particularly preferredembodiment form is effected by way of a hot-melt adhesive which connectsthe parts to one another, but it may also be effected in a mechanicalmanner. Usefully the adhesive location at surrounding temperature has astrength which is sufficient only for a plastic deformation but issmaller than the breaking strength of the material layer in order tosafely rule out any damage to the material layer. As a hot-melt adhesiveone preferably uses a polymer with polar side-groups which is solid atroom temperature and which softens or melts at temperatures of above 150C. Such polymers are known and are obtainable on the market, such ase.g. copolymers with vinyl acetate, acrylates or acrylic acid, as wellas hot-melt adhesives based on ionomers.

The method according to the invention is particularly suitable forapplication in the repair of bodies of vehicles, wherein the materiallayer consists of metal sheet, in particular steel sheet and anyoccuring cover layers are removed before adhesing to the connectionelement when their adhesive strength on the material layer is smallerthan the required tensile strength of the adhesive location.

Embodiment examples of the invention are now explained in more detail byway of the figures. There are shown in:

FIG. 1 a semi-schematic representation of a device according to theinvention in a lateral view;

FIG. 2 a part of the device of FIG. 1 in a plan view;

FIG. 3 a a support device according to the invention in a lateral view;

FIG. 3 b another support device according to the invention in a lateralview and

FIG. 4 the schematic representation of an adhesive location on carryingout the method according to the invention.

FIG. 1 shows a planishing device 10 according to the invention with twolever arms 151.1, 151.2, with a joint member 157, with a supportingelement 16 and support means 162.1, 162.2. The lever arms 151.1, 151.2at their free end in each case have a grip 163.2 which is shownschematically at the second lever arm 151.2. Each lever arm 151.1, 151.2at the end 158.1, 158.2 lying opposite the grip is connected to thejoint member 157 in each case via a joint (here a pivot joint).Additionally the lever arms 151.1, 151.2 at a distance d1 from thesepivot joints are likewise connected to the support means 162.1, 162.2 inan articulated manner. With this embodiment example these jointconnections have a pivot or a pivot stub mounted in a slot-like opening156 of the lever arms 151.1, 151.2. The supporting element 16 with thisembodiment form is a straight rail on which the support means 162.1,162.2 formed as slides are displaceable. These slides may be locked in adesired position on the arm by way of adjusting means 164.1, 164.2, e.g.wing nuts. The arm 16 is interactively connected at its ends in eachcase to bearing elements 12.1, 12.2, wherein these are adjustable inheight with respect to the arm 16.

The pulling element 11 is adjustably connected to the joint member 157by way of an adjusting head 155 via a rod 154 which is at least partlyprovided with a thread. The adjustability has the effect that the ratioof the distance d3 between the bearing elements 12.1, 12.2 to themaximal path d2 of the pulling element 11 is at least 10:1, preferablyat least 20:1. The pulling element or the rod 154 is preferably guided,here by guiding slots or a bore 71, so that a defined force effect isensured. The arrangement according to the invention has the effect thaton actuation of the lever arms 151.1, 151.2 in the direction of theworkpiece to be treated, the pulling element moves away from this andtravels a desired part path of the maximal path d2. It is ensured thateven with a non-uniform force effect on the lever arms 151,1, 152.2 thepulling element is uniformly moved away from the dent location and noundesired force components are introduced into the workpiece.

The pulling element 11 here at its free operating end 68 comprises acoupling means 69. This coupling means 69 permits a releasableconnection to a connection element 13 which is connectable to the dentlocation to be deformed. In this embodiment example this coupling means69 is formed by a recess in the region of the operating end 68 of theconnection element 13, which preferably contains a catch mechanism, forexample a flute or a groove so that the connection element 13 may notonly be loosely inserted into the recess, but may find a secure holdtherein. If desired one may also use alternative coupling means, e.g. arigidly catching bayonette connection.

The design of the arm 16 with the slide may be easily recognised fromFIG. 2, which shows a preferred embodiment form of the arm 16 with twodistanced, straight rail parts 165.1, 165.2. With particular embodimentforms the support means 162.1, 162.2 may be additionally fixed atvarious positions of the supporting element 16 so that their mutualdistance d3 may be varied. A particular advantage of the invention liesin the fact that the planishing device may be adjusted very flexiblyaccording to its object and may be adapted practically to allconceivable workpiece geometries, but that the distance d3 between thebearing elements 12.1, 12.2 remains constant during the application ofthe tool and thus one achieves a secure and exact support whilstavoiding the disadvantages of the state of the art. In particular,compared to the initially mentioned single lever designs and U.S. Pat.No. 4,026,139, it is clear that the distance d3 although able to beadjusted, on application of the tool however does not undesirably changeand no joint arrangements are necessary, which render the tool instable(cf. the pivot joint 32 in U.S. Pat. No. 4,026,139). Furthermore withthe solution according to the invention the distance between the pullingelement and the bearing elements 12.1, 12.2 remains constant. By way ofthis there are effected no undesired force components transverse to thesurface of the material, which would very disadvantageously affect theapplication of a connection element 13 to be adhesed on account of theshear forces occuring in the adhesive location. The device according tothe invention permits the deformation forces to be transmittedessentially perpendicular to the dent region (B) and a largelyhomogeneous flow of force.

With particular embodiment forms the supporting arm may differ from thestraight rail form. In order to achieve a greater lift distance d2 (cf.FIG. 1) the supporting arm in the middle region may e.g. have ayoke-like, upwardly pointing geometry. In this case the support means162.1, 162.2 remain displaceable on straight rail parts in the abovedescribed manner. Such yoke-like transitions may be mechanicallyconnected to the rail parts or formed as one piece with these.

FIG. 3 a shows a bearing element 12 in a lateral view. The arrangementof a three-axis joint which here is designed as a ball joint isparticularly favourable. This permits the foot 52 of the bearing element12 to move spacially so that the planishing device 10 may also beapplied on spacially arcuate material parts in the desired angularposition. According to the invention the foot 52 of the bearing elementhas as large a surface as possible which with a tool for planishing carbodies is approx. 20-30 cm2, and here is shaped in a circular manner.With a preferred variant of the bearing element 52 this has a fasteningmeans 55 which may be temporarily connected and released to and from thematerial layer WS, such as e.g. a magnet or a suction pad.

In FIG. 3 b there is shown a further preferred embodiment form of thebearing element 12. In order to achieve an improved distribution of thecounterforces on the workpiece counteracting the pulling force and toensure a good bearing with arcuate workpieces, the bearing element 12 ishere provided with two feet 52.1, 52.2. The bearing element 12 isconnected to the supporting element 16 in an articulated manner via aball joint 56. The two feet 52.1, 52.2 are movably arranged with respectto the supporting arm via adjusting means 57.1, 57.2, 57.3, 57.4, herefor example adjusting nuts, joint and length/axis position adjustment(also rotation). Of course also for each of the feet 52.1, 52.2 theremay be provided a ball joint as an adjusting means. The bearing surfacesof each of the feet in comparison to the foot shown in FIG. 3 a may besuitably smaller without unallowable pressure effects arising on thematerial surface. Furthermore this arrangement has the advantage thatthe tool may be supported with respect to the workpiece even withworking regions which are difficult on account of the geometric nature.

The method according to the invention is explained in more detail by wayof FIG. 4. A dent B in a material layer WS, e.g. the steel sheet of avehicle body is to be repaired. On the material layer WS roughly in themiddle of the dent region B the connection element 13 with its endsurface 61 is pressed onto a hot-melt adhesive 19 which has beenliquefied by prior heating action. After the cooling of the hot-meltadhesive 19 the connection element 13 is connected so rigidly to thematerial layer WS that a pulling of this layer in the dent region in thedirection of the arrow Z leads to a plastic deformation of the materiallayer.

The connection element 13 consists essentially of an end surface 61, atransition piece 62 and a coupling head 63 which releasably cooperateswith the coupling means 69 of the pulling element 15. The coupling head63 preferably catches in a recess or flute of the coupling means 69, sothat under the pulling effect the coupling head 63 is not undesirablyreleased from the coupling means 69. In a preferred embodiment form thecoupling head 63 has a centering geometry, for example a conical form,so that the application of the tool and the catching with the couplingmeans 69 is simplified. The arrangement of the pulling element 11 andthe connection element 13 is selected such that the forces transmittedvia the lever arms 151.1, 151.2 (cf. FIG. 1) act as perpendicularly aspossible on the material layer WS in order to effect a uniformplanishing of the dent location B.

The maximal path d2 (cf. FIG. 1) of the pulling element 15 in thedirection of the arrow Z according to the invention is limited butvariably adjustable. In order to achieve an adaptation to the depth of adent B one may vary the length d4, e.g. in that a set of connectionelements 13 with differing lengths of the transition piece 62 are madeavailable. Within the framework of the method a force (F) is to beintroduced essentially perpendicular to the dent region (B) by actuatingthe lever arms 151.1, 152.2.

The end surface 61 need not be formed level and may be adapted to theshape of a dent, e.g. in that its bearing region or practically thewhole element 13 consists of one material which may be adapted by way ofmachining away or thermal deformation to the respective dent shape, e.g.in that the bearing region consists of a thermoplast and in the plasticcondition before adhesion is pressed into the dent for adaptation toshape.

The actual planishing procedure is now effected as follows. Theconnection of a connection element 13 to the material layer WS iscarried out as previously described. Thereafter the support means 162.1,162.2 of the lever arms 151.1, 152.2 are adjusted and aligned withrespect to a supporting element as well as further setting parameters,such as adjustable feet 52 of the bearing elements. Thereafter thepulling element 11 is connected to the connection element 13 via thecoupling 63, 69 and the bearing elements 12.1, 12.2 are applied on theworkpiece to be treated at the desired location. By way of actuating thelever arms 151.1, 151.2 a force F which is essentially perpendicular tothe dent region B is exerted onto this dent region. After the desiredplastic deformation of the dent as a rule firstly the tool is removed byreleasing the coupling from the connection element 13 and finally theconnection between the connection element 13 and the material layer WSis released.

The inventive concept obviously includes embodiment examples with whichthe grips of the lever arms 151.1, 151.2 may be actuated in aco-ordinated manner by way of an auxiliary design which likewise may beguided or supported by the rod 154.

1. A planishing device with a pulling element and lever arms connectedin an articulated manner as well as bearing elements for bearing on amaterial layer, characterised in that the lever arms in the region ofeach end lying opposite each grip are connected in an articulated mannerto a joint member connecting the lever arms, and the lever arms at alocation distanced from each end are supported in an articulated andmovable manner via stationary support means slidably positonable on asupporting element interactively connected to the bearing elements, andthat the pulling element is connected to the joint member.
 2. Aplanishing device for repairing a dent in a metal sheet, comprising: ajoint member; a supporting arm with a bearing element at each end; twolever arms having inner ends interconnected to each other in anarticulated manner via said joint member; a support mounted on saidsupporting arm, said support articulatingly engaging each of said leverarms at a distance from said inner ends with joint connections whilemaintaining each of said lever arms at said joint connections in a setseparation from said supporting arm; a connecting element positioned bysaid joint member and said supporting arm, to be temporarily attached toa surface of the metal sheet; a pulling element connected to saidconnecting element, said pulling element being adjustably interconnectedto said joint member; and grips formed by distal ends of said lever armseach implementing a force manually applied to said grips in a directiontoward said supporting arm, to remove a dent in the metal sheet.
 3. Theplanishing device according to claim 1, wherein the joint member isarranged between the joint connections of each support mean.
 4. Theplanishing device according to claim 1, wherein an end surface of theconnecting element consists of a material which is attachable by way ofa hot-melt adhesive to the surface of the metal sheet to be repaired. 5.The planishing device according to claim 2, wherein the hot-meltadhesive comprises a polymer with polar side-group which is solid atroom temperature and which softens or melts at temperatures of above 150C.
 6. The planishing device according to claim 5, wherein the polymer isone out of a group of copolymer with vinyl acetate, acrylates, acrylicacid or based on ionomers.
 7. The planishing device according to claim3, wherein the end surface of the connecting element is adoptable to theshape of a dent.
 8. The planishing device according to claim 2, whereinthe pulling element is interconnected to the joint member by way of arod and an adjusting head.
 9. The planishing device according to claim2, wherein the rod is guided in a slot or in a bore so that a definedforce effect is ensured.
 10. The planishing device according to claim 2,wherein the supporting element is a straight rail and the support meansare formed as slides mounted in a displaceable manner on the supportingarm.
 11. The planishing device according to claim 10, wherein thesupport means, are lockable in a desired position on the supporting armby way of adjusting means.
 12. The planishing device according to claim2, wherein the supporting arm comprises two straight rail parts.
 13. Theplanishing device according to claim 2, wherein the pulling element isadjustably connected to the joint member in a manner such that themaximal path of the pulling element is adjustable.
 14. The planishingdevice according to claim 2, wherein the bearing elements are arrangedon the supporting arm such that the foot of the bearing elements isadjustable with respect to the supporting element with regard to thedistance d1 and/or angular position.
 15. The planishing device accordingto claim 14, wherein the bearing element have at least two feet.
 16. Theplanishing device according to claim 2, wherein at least one foot of thebearing elements has a fastening means which is temporarily connectableand releasable to and from the material layer.
 17. The planishing deviceaccording to claim 2, wherein the linkage location of the joint memberand of the support means of the lever arms and the grips of the leverarms are distanced from one another in a manner such that the lever armshave a transmission ratio of at least 1:3.
 18. A method for removing adent in a metal sheet material by a planishing device, comprising thesteps of: a) attaching an end surface of a connecting element to asurface of a metal sheet in the region of a dent by a hot melt adhesive;b) applying bearing elements of the planishing device to the metalsheet; c) adjusting height and position of the bearing elements and apulling element with respect to the connecting element; d)interconnecting the connecting element of the planishing device via thepulling element with inner ends of a pair of lever arms of theplanishing device which are each at a distance d1 from their inner endsupported in an articulated manner by a joint connection on a supportmean mounted on the supporting arm; e) exerting a force essentiallyperpendicular onto the dent region by pressing the outer ends of thelever arms in the direction of the supporting arm such that the dent isplastically deformed; and f) releasing the connection between theconnection element and the material layer.
 19. A method according toclaim 18, wherein the hot melt adhesive comprises a polymer with polarside-group which is solid at room temperature and which softens or meltsat temperatures of above 150 C.
 20. A method according to claim 19,wherein the polymer is one out of a group of copolymer with vinylacetate, acrylates, acrylic acid or based on ionomers.
 21. A methodaccording to claim 18, wherein the end surface of the connecting elementis adoptable to the shape of the dent.
 22. A method according to claim18, wherein the adjusting of the position of the bearing elements andthe pulling element with respect to the connecting element is done bysliding the support means along the supporting arm which is built out asstraight rail.
 23. A planishing device for repairing a dent in a metalsheet, comprising: a joint member; a plurality of bearing elements; asupporting arm exhibiting a length terminated at each end by one of saidbearing elements; two lever arms having inner ends interconnected toeach other in an articulated manner via said joint member; a connectingelement positioned by said joint member and said supporting arm, to betemporarily attached to a surface of the metal sheet; a pulling elementconnected to said connecting element, said pulling element beingadjustably interconnected to said joint member; a support articulatinglyengaging each of said lever arms at a distance from said inner ends,said support being slidably mounted on said supporting arm to adjustablyposition said pulling element along said length; and grips formed bydistal ends of said lever arms each implementing a force manuallyapplied to said grips in a direction toward said supporting arm, toremove a dent in the metal sheet.
 24. A planishing device for repairinga dent in a metal sheet, comprising: a joint member; a supporting armwith a bearing element at each end; two lever arms having inner endsinterconnected to each other in an articulated manner via said jointmember; a support mounted on said supporting arm, said supportarticulatingly engaging each of said lever arms at joint connectionsformed by fulcrums positioned at a distance from said inner ends; aconnecting element positioned by said joint member and said supportingarm, to be temporarily attached to a surface of the metal sheet; apulling element connected to said connecting element, said pullingelement being adjustably interconnected to said joint member; and gripsformed by distal ends of said lever arms each implementing a forcemanually applied to said grips in a direction toward said supportingarm, to remove a dent in the metal sheet.
 25. A planishing device forrepairing a dent in a metal sheet, comprising: a joint member; asupporting arm with a bearing element at each end; two lever arms havinginner ends interconnected to each other in an articulated manner viasaid joint member; a support providing spaced-apart projections rigidlyextending from said supporting arm, said support articulatingly engagingeach of said lever arms at a distance from said inner ends with jointconnections while enabling said lever arms to place said joint member inproximity to said supporting arm; a connecting element positioned bysaid joint member and said supporting arm, to be temporarily attached toa surface of the metal sheet; a pulling element connected to saidconnecting element, said pulling element being adjustably interconnectedto said joint member; and grips formed by distal ends of said lever armseach implementing a force manually applied to said grips in a directiontoward said supporting arm, to remove a dent in the metal sheet.